New paper unexpectedly finds diverging trends in global temperature & radiative imbalance from greenhouse gases – Published in Geophysical Research Letters


By: - Climate DepotJuly 20, 2014 9:09 PM

New paper unexpectedly finds diverging trends in global temperature & radiative imbalance from greenhouse gases

http://hockeyschtick.blogspot.com/2014/07/new-paper-unexpectedly-finds-diverging.html

Unsettled science:

A new paper published in Geophysical Research Letters finds that the radiative imbalance from greenhouse gases at the top of the atmosphere has increased over the past 27 years while the rate of global warming has unexpectedly decreased or ‘paused’ over the past 15+ years.

This finding contradicts expectations from AGW theory of increased ‘heat trapping’ from increased greenhouse gases. However, the finding is consistent with radiosonde observations showing that outgoing longwave radiation to space from greenhouse gases has unexpectedly increased rather than decreased over the past 62 years, inconsistent with more heat being “trapped” in the mid-upper troposphere. 

According to the authors, the radiative imbalance from 1985-1999 was less than from 2000-2012 during the ‘pause’ in global surface temperatures. 

“Over the 1985-1999 period mean N [radiative imbalance] (0.34 ± 0.67 WM–2) is lower than for the 2000-2012 period (0.62 ± 0.43 WM–2, uncertainties at 90% confidence level) despite the slower rate of surface temperature rise since 2000.”

The authors find that the radiative imbalance at the top of the atmosphere is correlated to natural variability including ENSO and volcanic eruptions:

“While the precise magnitude of [radiative imbalance] remains uncertain, the reconstruction captures interannual variability which is dominated by the eruption of Mt. Pinatubo in 1991 and the El Niño Southern Oscillation.”

However, Willis Eschenbach has shown radiative imbalances at the top of the atmosphere from the Pinatubo eruption have had essentially no effect on surface temperatures, which is observational evidence that emergent thermodynamic phenomena control temperature and the climate, rather than radiative imbalance from greenhouse gases at the top of the atmosphere.

Changes in global net radiative imbalance 1985-2012Richard P. Allan, et al

AbstractCombining satellite data, atmospheric reanalyses and climate model simulations, variability in the net downward radiative flux imbalance at the top of Earth’s atmosphere (N) is reconstructed and linked to recent climate change. Over the 1985-1999 period mean N (0.34 ± 0.67 WM–2) is lower than for the 2000-2012 period (0.62 ± 0.43 WM–2, uncertainties at 90% confidence level) despite the slower rate of surface temperature rise since 2000. While the precise magnitude of N remains uncertain, the reconstruction captures interannual variability which is dominated by the eruption of Mt. Pinatubo in 1991 and the El Niño Southern Oscillation. Monthly deseasonalized interannual variability in N generated by an ensemble of 9 climate model simulations using prescribed sea surface temperature and radiative forcings and from the satellite-based reconstruction is significantly correlated (r ∼ 0.6) over the 1985-2012 period.